Signaling pathways in cells historically have been studied using in vitro assays, where components are purified from cells and the reactions are done in a test tube. These assays can be helpful in identifying key players of signaling pathways, however these in vitro assays cannot mimic the complex environment and interactions found in the cytoplasm of an intact cell. Several important signaling pathways involved in maintaining healthy tissue and preventing disease are the kinases, which phosphorylate proteins in response to specific upstream signals. Recent advances in nanoparticle technology are starting to make visualization of cellular events in vivo, in real time, possible. We propose to use two different bioconjugated nanoparticles (BNPs) to visualize and localize kinase activity, using one BNP, and, with the second BNP, we will specifically inhibit kinase activity and release that inhibition with a specific, external signal.